EMC Corporation's DiskXtender® is an automated, policy-based, file system-centric solution for migrating inactive data off higher-cost storage to lower-cost disk, tape, or optical devices. In many environments, a majority of data can be categorized as inactive because the data is either not modified or accessed for a long period of time, but the data is still stored on primary storage. This inactive data may result in a growth in capacity for production storage, which increase costs for storage, protection, disaster recovery and management. DiskXtender® implements a file-system filter driver that intercepts user mode Input/Output requests. These intercepted requests are then processed by DiskXtender® components, which are capable of detecting inactive data and migrating the inactive data to secondary and/or tertiary storage with lower costs while still maintaining transparency to both applications and end users. Applications and end users have full visibility of migrated data, and the migrated data will either be redirected to users and applications or copied back to the production system when access is requested. When necessary, files are fetched off of secondary storage media and then passed back to the calling applications. Otherwise, if no processing is necessary, the filter driver does nothing and simply passes the request through the stack of lower level drivers. A hard disk drive for which DiskXtender® migrated inactive data to secondary storage is referred to as an extended drive, while directories on the extended drive that DiskXtender® manages are referred to as media folders.